Monoclonal antibodies in the management of asthma: Dead ends, current status and future perspectives

The effect of Bruton's tyrosine kinase (BTK) inhibitor in the eosinophilic asthma model of mouse

Bruton's Tyrosine kinase (BTK) plays a pivotal role as the key mediator in B cell signaling. Recent research has revealed that it is also expressed in cells critical to asthma development, such as T cells, and eosinophils. This study aims to investigate the potential of BTK inhibitor in eosinophilic asthma mouse model. BALB/c mice were sensitized with ovalbumin (OVA) via intraperitoneal injections and followed by OVA nebulizations. The mice were treated with 250 µg/ml or 500 µg/ml of ibrutinib before the second intraperitoneal injection and the first nebulization. Two days after the last OVA challenge, airway hyperresponsiveness (AHR) was assessed with methacholine, and differential cell count in bronchoalveolar lavage fluid (BALF) was performed. The cytokines were measured in BALF, and serum OVA-specific IgE and IgG antibody levels were evaluated by ELISA. The inhibitory effect of ibrutinib was also evaluated in splenic mononuclear cells, mast cells, eosinophils, and T cells in vitro. Treatment with ibrutinib significantly attenuated AHR and airway inflammation, compared to the OVA-induced positive control. The treatment also reduced IL-4, IL-5, IL-13 and IFN-γ cytokine levels and suppressed OVA-specific IgE and IgG production compared to the OVA-induced positive control. Additionally, ibrutinib decreased beta-hexosaminidase release from mast cells, type 2 cytokine productions from mononuclear cells and T cells, and eosinophilic activation markers in vitro. The results of this study suggest that ibrutinib treatment could exert anti-allergic effects by inactivating B cells and other BTK-expressing cells. Further studies are needed to investigate the potential therapeutic effect of ibrutinib on allergic diseases.

Efficacy and Safety of Monoclonal Antibodies for the Treatment of Eosinophilic Esophagitis: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

BACKGROUND AND AIMS

Monoclonal antibodies (MAbs) have clinical benefits for treating several atopic diseases. However, consensus on its use for eosinophilic esophagitis (EoE) is lacking. The present meta-analysis aimed to compare the efficacy and safety of MAbs versus placebo for treating EoE.

METHODS

We searched PubMed, Embase, and Cochrane Library for randomized controlled trials (RCTs). The primary outcomes were changes in peak esophageal eosinophils count/high power field (HPF) and mean esophageal eosinophils count/HPF. The secondary outcomes were changes in the EoE-Histology Scoring System (EoE-HSS), Endoscopic Reference Score (EREFS), dysphagia score, and adverse events (AEs). We compared binary outcomes using risk ratio (RR) and continuous outcomes using mean difference (MD) or standardized mean difference (SMD), with 95% confidence interval (CI). Considering the diversity of mechanistic properties of MAbs, a pre-specified subgroup analysis by MAb mechanism of action was performed for all outcomes, provided that at least two studies were in each subgroup. Heterogeneity was assessed using Cochran's Q test and I2 statistics.

RESULTS

6 RCTs were included (533 patients). Compared to placebo, MAbs led to a significant reduction in peak esophageal eosinophils count/HPF (MD -0.78; CI 95% -0.87, -0.6801) and mean esophageal eosinophils count/HPF (SMD -0.79; CI 95% -1.5, -0.08). Moreover, MAbs significantly reduced EoE-HSS scores (grade score: SMD -9.31; 95% CI -13.95, -4.6701; stage score: SMD -10.18; 95% CI -15.06, -5.31), EREFS (SMD -5.95; CI 95% -9.19, -2.71) and dysphagia score (SMD -1.79; CI 95% -3.36, -0.23) without increasing AEs compared to placebo. Among those MAbs whose mechanism of action includes the blockage of the receptor for IL-13 (Dupilumab, QAX576, and RPC4046), the scores of EoE-HSS grade, EoE-HSS stage, EREFS, and dysphagia were significantly reduced, and they presented a similar risk of overall and serious AEs compared to placebo.

CONCLUSION

MAbs seem effective and safe in reducing esophageal eosinophil infiltrate, EoE-HSS score, EREFS score, and dysphagia symptoms in patients with EoE. However, further evidence is needed to establish its place in EoE management.

Eosinophil to lymphocyte ratio may predict OCS reduction and change in quality of life (AQLQ) resulting from asthma biological treatment

OBJECTIVES

Simple clinical parameters that could be helpful in choice of monoclonal antibodies and prediction of their effectiveness are being sought. The aim was to assess if neutrophil-to-lymphocyte, eosinophil-to-lymphocyte and platelet-to-lymphocyte ratios may predict outcomes of biologic therapy for severe asthma.

METHODS

Retrospective, single-center study including severe asthma patients treated with three different biologics. The blood ratios were assessed at initiation of treatment (point 0) and after six months (point 1). The chi-square test was used to analyze differences in nominal variables. Quantitative variables were compared by Student's t-test, Mann-Whitney U or Wilcoxon signed-rank tests.

RESULTS

53 patients with severe asthma were included, among them 21 patients (40%) treated with omalizumab and 32 patients (60%) with mepolizumab or benralizumab. Neutrophil-to-lymphocyte and platelet-to-lymphocyte ratios did not change during six-month-course of biological treatment. Eosinophil-to-lymphocyte ratio was higher at the point 0 (p = 0.016) in the group treated with anti-eosinophils than in the omalizumab group and lower at the point 1 (p = 0.006). In the anti-eosinophil group this ratio decreased between points 0 and 1 (p < 0.001). In the omalizumab group there was an inverse correlation between the initial ratio and oral corticosteroid dose reduction (rs = -0,67). In the a/eos group there were significant correlations between initial ratio and age (rs = 0.36), and ACQ (rs = -0.4) and ACQ (rs = 0.41) measured at the point 1.

CONCLUSIONS

Pretreatment eosinophil-to-lymphocyte ratio may predict oral corticosteroid dose reduction resulting from omalizumab treatment and change in quality of life and asthma control resulting from anti-IL-5 and IL-5R treatment.

New targets for type 2-low asthma

Asthma is characterized by airway obstruction and inflammation, and presents significant diagnostic and treatment challenges. The concept of endotypes has improved understanding of the mechanisms of asthma and has stimulated the development of effective treatment strategies. Sputum profiles may be used to classify asthma into two major inflammatory types: type 2-high (T2H) and type 2-low (T2L) asthma. T2H, characterized by elevated type 2 inflammation, has been extensively studied and several effective biologic treatments have been developed. However, managing T2L is more difficult due to the lack of reliable biomarkers for accurate diagnosis and classification. Additionally, conventional anti-inflammatory therapy does not completely control the symptoms of T2L; therefore, further research is needed to identify effective biologic treatments. This review provides new insights into the clinical characteristics and underlying mechanisms of severe T2L and investigates potential therapeutic approaches to control the disease.

Biologics, theranostics, and personalized medicine in drug delivery systems

The progress in human disease treatment can be greatly advanced through the implementation of nanomedicine. This approach involves targeted and cell-specific therapy, controlled drug release, personalized dosage forms, wearable drug delivery, and companion diagnostics. By integrating cutting-edge technologies with drug delivery systems, greater precision can be achieved at the tissue and cellular levels through the use of stimuli-responsive nanoparticles, and the development of electrochemical sensor systems. This precision targeting - by virtue of nanotechnology - allows for therapy to be directed specifically to affected tissues while greatly reducing side effects on healthy tissues. As such, nanomedicine has the potential to transform the treatment of conditions such as cancer, genetic diseases, and chronic illnesses by facilitating precise and cell-specific drug delivery. Additionally, personalized dosage forms and wearable devices offer the ability to tailor treatment to the unique needs of each patient, thereby increasing therapeutic effectiveness and compliance. Companion diagnostics further enable efficient monitoring of treatment response, enabling customized adjustments to the treatment plan. The question of whether all the potential therapeutic approaches outlined here are viable alternatives to current treatments is also discussed. In general, the application of nanotechnology in the field of biomedicine may provide a strong alternative to existing treatments for several reasons. In this review, we aim to present evidence that, although in early stages, fully merging advanced technology with innovative drug delivery shows promise for successful implementation across various disease areas, including cancer and genetic or chronic diseases.

Repositioning baloxavir marboxil as VISTA agonist that ameliorates experimental asthma

V-type immunoglobulin domain-containing suppressor of T-cell activation (VISTA), a novel negative checkpoint regulator, plays an essential role in allergic pulmonary inflammation in mice. Treatment with a VISTA agonistic antibody could significantly improve asthma symptoms. Thus, for allergic asthma treatment, VISTA targeting may be a compelling approach. In this study, we examined the functional mechanism of VISTA in allergic pulmonary inflammation and screened the FDA-approved drugs for VISTA agonists. By using mass cytometry (CyTOF), we found that VISTA deficiency primarily increased lung macrophage infiltration in the OVA-induced asthma model, accompanied by an increased proportion of M1 macrophages (CD11b+F4/80+CD86+) and a decreased proportion of M2 macrophages (CD11b+F4/80+CD206+). Further in vitro studies showed that VISTA deficiency promoted M1 polarization and inhibited M2 polarization of bone marrow-derived macrophages (BMDMs). Importantly, we discovered baloxavir marboxil (BXM) as a VISTA agonist by virtual screening of FDA-approved drugs. The surface plasmon resonance (SPR) assays revealed that BXM (KD = 1.07 µM) as well as its active form, baloxavir acid (BXA) (KD = 0.21 µM), could directly bind to VISTA with high affinity. Notably, treatment with BXM significantly ameliorated asthma symptoms, including less lung inflammation, mucus secretion, and the generation of Th2 cytokines (IL-5, IL-13, and IL-4), which were dramatically attenuated by anti-VISTA monoclonal antibody treatment. BXM administration also reduced the pulmonary infiltration of M1 macrophages and raised M2 macrophages. Collectively, our study indicates that VISTA regulates pulmonary inflammation in allergic asthma by regulating macrophage polarization and baloxavir marboxil, and an old drug might be a new treatment for allergic asthma through targeting VISTA.

Decoding treatment efficacy: uncovering response and failure dynamics to biologics in asthma

INTRODUCTION

Asthma is a global health problem, with alarming prevalence and mortality rates. Biologic therapies, particularly monoclonal antibodies such as omalizumab, have emerged as promising alternatives, targeting specific immune pathways. This article assesses the efficacy of these biologics in asthma management and attempts to reveal factors associated with their response and failure dynamics.

AREA COVERED

This article explores the efficacy of biologics in asthma, biomarkers, and the relationship between asthma phenotypes (including eosinophilic and non-eosinophilic (neutrophilic) types) and biologic treatments; particularly their effectiveness for each subtype.

EXPERT OPINION

Personalized asthma management that incorporates molecular insights as well as individual variations is of outmost necessity. An emphasis is put on immunological profiling, understanding comorbidities and considering individual patient factors when managing asthma. Cutting-edge phenotyping tools including omic technologies play a crucial role in improving asthma management precision. Variability in patient responses to biologic treatments such as non-responders, partial responders and super responders poses a formidable challenge to effective asthma care management strategies.

Potential of MAIT cells to modulate asthma

Despite recent advances in asthma treatments, the search for novel therapies remains necessary because there are still patients with recurrent asthma exacerbations and poor responses to the existing treatments. Since group 2 innate lymphoid cells (ILC2) play a pivotal role in asthma by triggering and exacerbating type 2 inflammation, controlling ILC2s function is key to combating severe asthma. Mucosal-associated invariant T (MAIT) cells are innate-like T cells abundant in humans and are activated both in a T cell receptor-dependent and -independent manner. MAIT cells are composed of MAIT1 and MAIT17 based on the expression of transcription factors T-bet and RORγt, respectively. MAIT cells play pivotal roles in host defense against pathogens and in tissue repair and are essential for the maintenance of immunity and hemostasis. Our recent studies revealed that MAIT cells inhibit both ILC2 proliferation and functions in a mouse model of airway inflammation. MAIT cells may alleviate airway inflammation in two ways, by promoting airway epithelial cell barrier repair and by repressing ILC2s. Therefore, reagents that promote MAIT cell-mediated suppression of ILC2 proliferation and function, or designer MAIT cells (genetically engineered to suppress ILC2s or promote repair of airway damage), may be effective therapeutic agents for severe asthma.

Inhaled RNA drugs to treat lung diseases: Disease-related cells and nano-bio interactions

In recent years, RNA-based therapies have gained much attention as biomedicines due to their remarkable therapeutic effects with high specificity and potency. Lung diseases offer a variety of currently undruggable but attractive targets that could potentially be treated with RNA drugs. Inhaled RNA drugs for the treatment of lung diseases, including asthma, chronic obstructive pulmonary disease, cystic fibrosis, and acute respiratory distress syndrome, have attracted more and more attention. A variety of novel nanoformulations have been designed and attempted for the delivery of RNA drugs to the lung via inhalation. However, the delivery of RNA drugs via inhalation poses several challenges. It includes protection of the stability of RNA molecules, overcoming biological barriers such as mucus and cell membrane to the delivery of RNA molecules to the targeted cytoplasm, escaping endosomal entrapment, and circumventing unwanted immune response etc. To address these challenges, ongoing researches focus on developing innovative nanoparticles to enhance the stability of RNA molecules, improve cellular targeting, enhance cellular uptake and endosomal escape to achieve precise delivery of RNA drugs to the intended lung cells while avoiding unwanted nano-bio interactions and off-target effects. The present review first addresses the pathologic hallmarks of different lung diseases, disease-related cell types in the lung, and promising therapeutic targets in these lung cells. Subsequently we highlight the importance of the nano-bio interactions in the lung that need to be addressed to realize disease-related cell-specific delivery of inhaled RNA drugs. This is followed by a review on the physical and chemical characteristics of inhaled nanoformulations that influence the nano-bio interactions with a focus on surface functionalization. Finally, the challenges in the development of inhaled nanomedicines and some key aspects that need to be considered in the development of future inhaled RNA drugs are discussed.

Emerging applications and prospects of NFκB decoy oligodeoxynucleotides in managing respiratory diseases

Chronic respiratory diseases like asthma and Chronic Obstructive Pulmonary Disease (COPD) have been a burden to society for an extended period. Currently, there are only preventative treatments in the form of mono- or multiple-drug therapy available to patients who need to utilize it daily. Hence, throughout the years there has been a substantial amount of research in understanding what causes inflammation in the context of these diseases. For example, the transcription factor NFκB has a pivotal role in causing chronic inflammation. Subsequent research has been exploring ways to block the activation of NFκB as a potential therapeutic strategy for many inflammatory diseases. One of the possible ways through which this is probable is the utilisation of decoy oligodeoxynucleotides, which are synthetic, short, single-stranded DNA fragments that mimic the consensus binding site of a targeted transcription factor, thereby functionally inactivating it. However, limitations to the implementation of decoy oligodeoxynucleotides include their rapid degradation by intracellular nucleases and the lack of targeted tissue specificity. An advantageous approach to overcome these limitations involves using nanoparticles as a vessel for drug delivery. In this review, all of those key elements will be explored as to how they come together as an application to treat chronic inflammation in respiratory diseases.

Engineering bispecific T-cell engagers to deplete eosinophils for the treatment of severe eosinophilic asthma

Severe eosinophilic asthma (SEA) is characterized by elevated eosinophil counts in the blood and airway mucosa. While monoclonal antibody therapies targeting interleukin-5 (IL-5) and its receptor (IL-5Rα) have improved treatment, some patients remain unresponsive. We propose an alternative approach to eliminate eosinophils using T cells by engineering IL-5Rα × CD3 bispecific T-cell engagers (bsTCEs) that target both IL-5Rα on eosinophils and CD3 on T cells. We designed different formats of IL-5Rα × CD3 bsTCEs, incorporating variations in valency, geometry, and affinity for the target antigen binding. We identified the single-chain variable fragment (scFv)-Fc format with the highest affinity toward the membrane-proximal domain of IL-5Rα in the IL-5Rα-binding arm showed the most potent cytotoxicity against IL-5Rα-expressing peripheral eosinophils by activating autologous primary T cells from healthy donors. This study proposes IL-5Rα × CD3 bsTCEs as potential alternatives for SEA treatment. Importantly, it demonstrates the first application of bsTCEs in eliminating disease-associated cells, including eosinophils, beyond cancer cells.

Thymic Stromal Lymphopoietin (TSLP), Its Isoforms and the Interplay with the Epithelium in Allergy and Asthma

Thymic stromal lymphopoietin (TSLP) is a pleiotropic cytokine that has emerged as a critical player in the development and progression of allergy and asthma. It is primarily produced by epithelial cells and functions as a potent immune system activator. TSLP acts through interaction with its receptor complex, composed of the TSLP receptor (TSLPR) and interleukin-7 receptor alpha chain (IL-7Rα), activating downstream complex signalling pathways. The TSLP major isoform, known as long-form TSLP (lfTSLP), is upregulated in the airway epithelium of patients with allergic diseases. More research is warranted to explore the precise mechanisms by which short-form TSLP (sfTSLP) regulates immune responses. Understanding the dynamic interplay between TSLP and the dysfunctional epithelium provides insights into the mechanisms underlying allergy and asthma pathogenesis. Targeting TSLP represents an important therapeutic strategy, as it may upstream disrupt the inflammatory cascade and alleviate symptoms associated with allergic inflammation.

Revisiting asthma pharmacotherapy: where do we stand and where do we want to go?

Several current guidelines/strategies outline a treatment approach to asthma, which primarily consider the goals of improving lung function and quality of life and reducing symptoms and exacerbations. They suggest a strategy of stepping up or down treatment, depending on the patient's overall current asthma symptom control and future risk of exacerbation. While this stepwise approach is undeniably practical for daily practice, it does not always address the underlying mechanisms of this heterogeneous disease. In the last decade, there have been attempts to improve the treatment of severe asthma, such as the addition of a long-acting antimuscarinic agent to the traditional inhaled corticosteroid/long-acting β2-agonist treatment and the introduction of therapies targeting key cytokines. However, despite such strategies several unmet needs in this population remain, motivating research to identify novel targets and develop improved therapeutic and/or preventative asthma treatments. Pending the availability of such therapies, it is essential to re-evaluate the current conventional "one-size-fits-all" approach to a more precise asthma management. Although challenging, identifying "treatable traits" that contribute to respiratory symptoms in individual patients with asthma may allow a more pragmatic approach to establish more personalised therapeutic goals.

The Role of Eosinophil-Derived Neurotoxin and Vascular Endothelial Growth Factor in the Pathogenesis of Eosinophilic Asthma

Asthma is a chronic complex pulmonary disease characterized by airway inflammation, remodeling, and hyperresponsiveness. Vascular endothelial growth factor (VEGF) and eosinophil-derived neurotoxin (EDN) are two significant mediators involved in the pathophysiology of asthma. In asthma, VEGF and EDN levels are elevated and correlate with disease severity and airway hyperresponsiveness. Diversity in VEGF polymorphisms results in the variability of responses to glucocorticosteroids and leukotriene antagonist treatment. Targeting VEGF and eosinophils is a promising therapeutic approach for asthma. We identified lichochalcone A, bevacizumab, azithromycin (AZT), vitamin D, diosmetin, epigallocatechin gallate, IGFBP-3, Neovastat (AE-941), endostatin, PEDF, and melatonin as putative add-on drugs in asthma with anti-VEGF properties. Further studies and clinical trials are needed to evaluate the efficacy of those drugs. AZT reduces the exacerbation rate and may be considered in adults with persistent symptomatic asthma. However, the long-term effects of AZT on community microbial resistance require further investigation. Vitamin D supplementation may enhance corticosteroid responsiveness. Herein, anti-eosinophil drugs are reviewed. Among them are, e.g., anti-IL-5 (mepolizumab, reslizumab, and benralizumab), anti-IL-13 (lebrikizumab and tralokinumab), anti-IL-4 and anti-IL-13 (dupilumab), and anti-IgE (omalizumab) drugs. EDN over peripheral blood eosinophil count is recommended to monitor the asthma control status and to assess the efficacy of anti-IL-5 therapy in asthma.

Recent developments in the use of monoclonal antibodies targeting the type 2 cytokines for severe asthma treatment

Severe or refractory asthma is seen in approximately 5% of asthmatic subjects who have unsatisfactory symptom control despite adherence to high-dose inhaled glucocorticoid therapies resulting in significant morbidity, reduced quality of life with attendant implications for healthcare costs. Marked heterogeneity in symptoms and at the molecular phenotypic level are hallmarks of asthma resulting in the requirement of specifically targeted treatments to block the key pathways of the disease. Monoclonal antibody (mAb)-based biologics targeted at inhibition of the type 2 cytokines IL-4, IL-5 and IL-13 have become established as effective treatments for severe asthma, with significant clinical benefit seen in carefully selected patient populations that take asthma phenotypes and endotypes into account. The further development of reproducible and straightforward discriminatory biomarkers may aid identification of those patients most likely to benefit from treatment with these interventions.

Intervention effects of Trichinella spiralis excretory-secretory antigens on allergic asthma in mice

Allergic asthma is a chronic, heterogeneous and inflammatory respiratory disease, and there are few medicines at present. An increasing number of studies indicate that Trichinella spiralis (T. spiralis) and its excretory-secretory (ES) antigens are inflammatory modulator. Therefore, this study focused on the effects of T. spiralis ES antigens on allergic asthma. Asthma model was established by sensitizing mice with ovalbumin antigen (OVA) and aluminum hydroxide (Al[OH]₃), the asthmatic mice were interfered using T. spiralis 43 kDa protein (Ts43), T. spiralis 49 kDa protein (Ts49), and T. spiralis 53 kDa protein (Ts53), the important components of ES antigens, to establish ES antigens intervention models. Then, asthma symptom changes, weight changes, and lung inflammation of mice were evaluated. The results showed that ES antigens could relieve symptoms, weight loss, and lung inflammation caused by asthma in the mice, and the effect of combined intervention of Ts43, Ts49, and Ts53 was better. Finally, the effects of ES antigens on type 1 helper T (Th1) and type 2 helper T (Th2) immune responses, and the differentiation direction of T lymphocytes in mice were discussed by detecting Th1 and Th2 cell-related factors and the ratio of CD₄⁺/CD₈⁺ T cells. The results suggested that the ratio of CD₄⁺/CD₈⁺ T cells decreased and the ratio of Th1/Th2 cells increased. In conclusion, this study indicated that T. spiralis ES antigens could mitigate allergic asthma in the mice by changing the differentiation direction of CD₄⁺ and CD₈⁺ T cells and regulating the imbalance of Th1/Th2 cells ratio.

Baseline Characteristics of Patients Enrolled in Clinical Trials of Biologics for Severe Asthma as Potential Predictors of Outcomes

(1) Background: Over the past 20 years, monoclonal antibodies have been developed for the treatment of severe asthma, with numerous randomised controlled trials (RCTs) conducted to define their safety and efficacy. The growing availability of biologics, which until now have only been available for T2-high asthma, has been further enriched by the arrival of tezepelumab. (2) Methods: This review aims to evaluate the baseline characteristics of patients enrolled in RCTs of biologics for severe asthma to understand how they could potentially predict outcomes and how they can help differentiate between available options. (3) Results: The studies reviewed demonstrated that all biologic agents are effective in improving asthma control, especially with regard to reducing exacerbation rates and OCS use. As we have seen, in this regard, there are few data on omalizumab and none yet on tezepelumab. In analysing exacerbations and average doses of OCSs, pivotal studies on benralizumab have enrolled more seriously ill patients. Secondary outcomes, such as improvement in lung function and quality of life, showed better results-especially for dupilumab and tezepelumab. (4) Conclusion: Biologics are all effective, albeit with important differences. What fundamentally guides the choice is the patient's clinical history, the endotype represented by biomarkers (especially blood eosinophils), and comorbidities (especially nasal polyposis).

Severe Asthma Remissions Induced by Biologics Targeting IL5/IL5r: Results from a Multicenter Real-Life Study

Add-on biological therapy has proven to be effective in many patients with severe eosinophilic asthma. In this observational multicenter retrospective study, we report the results obtained with mepolizumab and benralizumab in severe asthmatics treated for 12 months in a real-life setting. In these patients, peripheral eosinophil levels, pulmonary function trends, exacerbation rates, systemic corticosteroid use, and symptom control were evaluated during the observation period, to understand which patients met all the criteria in order to be considered in disease remission. The percentage of remittent patients was 30.12% in the mepolizumab-treated subgroup, while in the benralizumab-treated subgroup, patients in complete disease remission were 40%, after 12 months. The results of this study confirm the efficacy of anti-IL-5 biologic drugs in the treatment of severe eosinophilic asthma in a real-life setting.

Emerging role for interferons in respiratory viral infections and childhood asthma

Respiratory syncytial virus (RSV) and Rhinovirus (RV) infections are major triggers of severe lower respiratory illnesses (sLRI) in infants and children and are strongly associated with the subsequent development of asthma. Decades of research has focused on the role of type I interferons in antiviral immunity and ensuing airway diseases, however, recent findings have highlighted several novel aspects of the interferon response that merit further investigation. In this perspective, we discuss emerging roles of type I interferons in the pathogenesis of sLRI in children. We propose that variations in interferon response patterns exist as discrete endotypes, which operate locally in the airways and systemically through a lung-blood-bone marrow axis. We discuss new insights into the role of interferons in immune training, bacterial lysate immunotherapy, and allergen-specific immunotherapy. Interferons play complex and diverse roles in the pathogenesis of sLRI and later asthma, providing new directions for mechanistic studies and drug development.